The present disclosure relates to an image forming apparatus including a mechanism for removing flying toner by sucking air from a toner storing portion of a developing portion, and relates to a toner collecting case for use in the image forming apparatus.
In an image forming apparatus, there may be a case where a peripheral temperature of a toner storing portion rises under the influence of peripheral air heated by a heating device. Toner is made of resin. As a result, when the peripheral temperature of the toner storing portion rises and the temperature of the toner rises, the fluidity of the toner is reduced. In addition, for the toner to be adhered to a photoconductor drum, the toner needs to be electrically charged. However, the temperature rise is a factor of reducing the amount of charged toner. When the fluidity of the toner or the amount of charged toner is reduced, a sufficient amount of toner may not adhere to the photoconductor drum, resulting in an image defect such as a reduced density. Thus, various technologies have been proposed to restrict the temperature rise of the toner in the toner storing portion. For example, there is known a conventional technology in which a cooling fan is used to send a cooling air to a vent passage for cooling the developing device.